Although now characterized by inhospitable deserts, the Arabian Peninsula was a green hot spot for migrating members of the human genus, Homo, at least 300,000 years ago, scientists say.

Stone tools found among fossils of antelopes, elephants and other animals at Saudi Arabia’s Ti’s al Ghadah site date to between 300,000 and 500,000 years ago, archaeologist Patrick Roberts and his colleagues say. At that time, the site was located in a grassy, vegetated region that enjoyed regular rains, the researchers report online October 29 in Nature Ecology & Evolution.

The new finds support the idea that the Arabian Peninsula had a climate friendly to either Homo sapiens or another Homo species that journeyed out of Africa a few hundred thousand years ago, say Roberts, of the Max Planck Institute for the Science of Human History in Jena, Germany, and his team.

Homo sapiens originated in Africa roughly 300,000 years ago. Traditionally, scientists have estimated that human migrations out of Africa began about 60,000 years ago. But recent finds on the Arabian Peninsula, including a human finger fossil from at least 86,000 years ago, have indicated that these dispersals began much earlier (SN: 5/12/18, p. 12).

Probable butchery marks on two animal fossils found at Ti’s al Ghadah indicate that hunting occurred there, the researchers say. And analyses of diet-related chemicals in 21 animal teeth unearthed at the Saudi site point to an ancient environment similar to modern-day grassy savannas in East Africa. Forms of carbon in the teeth reflected a grassy menu, and forms of oxygen indicated that the animals had regularly drunk water from ponds or other sources fed by rainfall.